The earliest studies of healing required the robbing of graves and
little mortal knowledge has ever advanced without being wrenched bodily from a
universe ill-desiring to yield it.
Sometimes a chirurgeon starts as a humble product of the streets
who seeks the knowledge to heal and help those they care about in whatever way
they can. More often, they begin as one of the learned who finds themselves
skulking in the shadows performing whatever deeds are necessary to further
their knowledge. Shunned in higher society of most "civilized" places
where magical healing is available, chirurgeons are considered little better
than ghouls. Seen as butchers and mocked as would be necromancers lacking the
true power of magic, they still flourish wherever the poor and desperate exist.
After all, when you need a healer and can't afford the "donations"
asked by a temple, some questions aren't worth asking.
Chirurgeons will join adventuring parties for the same reason any
other scholar might; in search of knowledge, glory, or for more personal
motivations. Perhaps starting adventurers simply needed someone who could patch
them together and found that their resources were sufficient to hire a
chirurgeon out of their laboratory and into pursuit of greater fortune. Perhaps
a soul who would otherwise have spent a life taking decided instead to try their hand
at giving back. Regardless, even if their companions fall never to rise again,
it simply means the chirurgeon will have new subjects with which to further
their understanding of the myriad living forms.